Seal for blast furnace hoppers



Feb. 3, 1959 I J. D. GEISER SEAL FOR BLAST FURNACE HOPPERS 5 Shgets-Sheet 1 I Filed April 20, 1954 INVENTOR.

Feb. 3, 1959 J. D. GEISER v 2,872,054

SEAL FOR BLAST FURNACE HOPPERS Filed' April 20, 1954 5 She etsSheet 3 IN VEN TOR.

Feb. 3, 1959 J, GEISER M 2,872,054

SEAL FOR BLAST FURNACE HOPPERS Filed April 20, 1954 INVENTOR. J's/4, .2). Gems-r1:

5 Sheets-Sheet 5 SEAL FOR BLAST FURNACE HOPPERS John D. Geiser, Lakewood, Ohio, assignor to lnterlake Iron Corporation, Cleveland, Ohio, a corporation of New York Application April 20, 1954, Serial No. 424,356

13 Claims. (Cl. 214-37) This invention relates to blast furnaces generally and more particularly to improvements in effecting a seal in a furnace which is equipped with a revolving small bell and hopper.

The improved seal is applicable to the type of blast furnace wherein a revolving small bell and hopper extend downwardly into the top of the furnace shaft and an annular space is provided between the outside wall of the hopper and the upper end of the furnace shaft so that the hopper can be rotated.

A singular difliculty encountered in the operation of a blast furnace equipped with a revolving small bell and hopper relates to the maintenance of an eifective seal against the escape of dust-laden furnace gases through the annular space between the revolving hopper and the top of the furnace shaft. This difficulty is more pronounced and more likely to occur in those furnaces which are operated under what is known in the art as a high pressure condition.

Briefly the foregoing objective may be accomplished by providing at least two sealing rings between a rotating portion of the hopper and the stationary part of the furnace and by introducing a material under pressure between the rings to overcome the gas pressure bearing against the bottom. In one form of the invention, water under pressure is introduced between the rings and, in another form, grease under pressure is introduced between them, but, in either case, the pressure is sufficient to overcome the gas pressure bearing against the bottom ring. Where water is used, provision is made for discharging any liquid, which escapes past the sealing rings, to a point outside the furnace, whereas in the case of grease under pressure, provision is made for any grease escaping the lower ring-to drip into the large bell hopper. In either case the rings operate to seal the furnace without creating excessive friction.

Accordingly, it is a principal object of this invention to provide a sealing arrangement for a blast furnace which may be simply assembled onto a furnace installation and may be readily replaced regardless of the size of the installation.

An additional object relates to the reduction in the wear of a sealing assembly to increase the useful life and reduce the maintenance.

' Briefly, the foregoing objectives are accomplished by providing spaced sealing rings on one of the relatively movable parts in the annular space between the revolving hopper and the top of the furnace shaft, coupled with the introduction of a fluid into the space between the rings under suflicient pressure to offset the gas pressure exerted against the rings. The fluid used may be a liquid, such as water, or an inert gas, such as the products of combustion of a heating unit. Preferably, the sealing rings are in the form of circular segmental sections with interfitting ends that may be assembled about the hopper through a removable wall section of the furnace structure without the necessity of dismantling the entire charging mechanism of the installation. In addition, the

Eatented Feb. 3, 1959 'ice j arrangement may include segmental retaining rings which are assembled around the sealing ring segments and are coupled together by clamps which may be adjusted to secure the sealing rings in proper relation about the re-' volving hopper.

In the drawings:

Fig. 1 is a vertical section of a furnace top and chargiing mechanism to which our invention may be applied;

Fig. 2 illustrates, in cross-section, the charging portion at the top of the blast furnace;

Fig. 3 is a sectional view of drive; I

Fig. 4 is a horizontal section through the charging hopper illustrating the segmental wall construction;

Fig. 5 illustrates a portion of the section of Fig. 4 with a wall segment removed;

Fig. 6 is a sectional view taken along the lines 66 in Fig. 4 to show the sealing chamber;

Fig. 7 is a top view of a portion of a sealing ring and its retaining ring clamp;

Fig. 8 illustrates the interfitting construction between adjacent ends of independent sealing ring segments, and

Fig. 9 is a side elevation, partly in section, of a modified form of sealing construction.

Referring now to Fig. 1 of the drawings, the top of the blast furnace shaft 10 is shown provided at its upper end with a small bell 11 and a large bell 12 arranged vertically in series with one another within a bell chamber 13. The small bell is secured to the lower end of a tube a portion of the hopper which is adapted to be raised and lowered with re spect to a small hopper by hoisting mechanism (not shown). The large bell 12 is attached to the lower end of a bell rod 21 which passes through the tube 15 and is adapted to be raised and lowered by a suitable hoisting mechanism, not completely shown in the drawings. The bottom of the hopper 20 is thus normally closed by the small bell 11, while the bottom of a hopper is normally closed by the large bell 12. A receiving hopper, or chute is mounted above the small hopper 20 and the contents of a skip car, indicated by the broken lines 31, are dumped into the chute whenever the car reaches the top of an inclined trackway 32.

The hopper 20, which projects downwardly into the bell chamber 13 through an opening 22 in the top of the chamber, is mounted for rotation with respect to the top of the furnace shaft, as best shown in Figs. 2 and 3 of the drawings, and is provided with a laterally extending circular flange 14 to which is attached a ring gear 16. The ring gear 16 meshes with a pinion 17 on a drive shaft 18 which is, in turn, driven by an electric motor or other suitable power means (not shown). Circumferentially spaced rollers 23 are shown journaled in bearings which are attached to the outer wall 33 of the bell chamber 13 by suitable brackets 26. The hopper 20 is thus supported for rotation on the rollers 23 which engage an annular trackway 27 attached to a flange 28 extending laterally from the upper end of the depending skirt or sleeve 29 surrounding the hopper. Additional sets of guide rollers 24 and 19 are carried by suitable brackets on the outer wall of the bell chamber and adjacent the ring gear 16 to bear on such ring. The sleeve 29 is secured to the hopper flange 14 through the sleeve flange 28.

When assembled, the sleeve 29 is disposed between the outer wall 33 of the bell chamber and an inner concentric wall 34 and rotates with the hopper 20 so that the annular space 35 between the walls provides a gas sealing chamber in the form of a labyrinth path within which the bottom of the sleeve 29 terminates short of the bottom. In the illustration of Figs. 1 to 8, water or other suitable fiuid may be introduced under pressure into the seal ing chamber thus formed through a conduit disposed between sets of upper and lower sealing rings 51 and 56 respectively. Any water that escapes past the sealing rings may be discharged through conduits 41 and 43.

As best shown in Figs. 2 and 6 of the drawings, the outer Wall 33 of the bell chamber 'is provided with a series of upper annular lands t and lower annular lands 58, providing grooves 52 and 53 on its internal surface for receiving the sealing rings 51 and 56' respectively. In a preferred form shown in the drawings, the sealing rings are in the form of interfitting segmental sections assembled in an annular course within the respective grooves. The seal is enhanced by the introduction of liquid from the conduit 40 into the annular space 54 between the sets of sealing rings and the pressure is such as 'to'oflset the pressure of any gas acting 'on the rings from Within the furnace body. The liquid serves additionally to lubricate the ring surfaces and thereby to reduce frictional wear.

In practice, it is desirable that the assembly and replacement of the sealing rings be accomplished in an efficient and simple manner. Accordingly, a portion 45 of the external wall 33 is constructed in the form of segmental sections 60, which may be connected together in gas-tight relation, as at 61 and 62, whereby any individual selected portion may be removed for inspection or maintenance or replacement of sealing rings. By making the sealing rings also in segments, the rings may be replaced merely by removing one segment of the portion 45, and successively withdrawing and replacing the ring segments.

As best shown in Fig. 8 of the drawings, the opposite ends 62 and 63 of each sealing ring segment may be tongued and grooved respectively to provide an inter-fitting relation with mating ends of other ring segments, thereby resulting in an interfitted annular sealing ring that will retain its assembled configuration without relative movement between adjacent ends.

Further, in accordance with this invention, the ring segments may be effectively secured in inter-fitted relation about the chamber wall by means of an encircling retaining ring 79 which may be made up of a plurality of segmental retaining ring sections each of which carries an apertured bolt receiving lug 71 at each free end thereof. Thus, the segmental sections of the retaining ring '70 may be individually inserted through one open wall section along with the corresponding segmental ring section which it is adapted to encircle and then be coupled to the next succeeding segmental retaining ring section by a bolt 73 and nut 74 to draw the adjacent lugs together about the sealing ring segments. The clamps between adjacent retaining ring segments will straddle the interfitted joint between adjacent sealing ring segments. When all of the sealing ring segments and retaining ring segments have been inserted and slid around through the ring grooves, the final clamp connection is adjusted so as to secure the proper degree offriction against the sleeve 29. $uitable adjustment for wear may be made in the same manner.

Fig. 9 is a vertical section through a part of the furnace illustrating a modification of the invention. in this form of the invention, parts which correspond to Figs. l and 2 bear the same reference characters. The formation of the wall 33 is somewhat different in that it may have a smooth walled cylindrical interior surface, except for the annular shoulder 8b which operates as an abutment for a ring 81 of packing material. Other packing rings such as 32, 83 and 34 may be disposed above the ring 81 but spaced apart by spacing rings 35, 36 and 87, all of which may be held in position by a gland 38 which for convenience in assembly may be in the form of a split ring. The pressure on the rings may be adjusted by the fastening members 89. A lubricant, such as grease, may be forced through a conduit 75 into the central cavity 9%), through an aperture in the spacing ring 86, and maintained at a pressure which is sufficient to overcome the pressure of the gas within the furnace. Any lubricant which may escape past the rings 32 and 81 will serve to 4 fill up the space 76 and thereafter will flow over the top of the wall 34 and drop "into the bell chamber 13.

If desired, an inert gas such as the flue gas of a boiler or of a blast furnace stove, may be utilized in place of grease, in which case the gas is supplied under sufficient pressure to overcome the pressure of the gas in the furnace.

I have shown and described what I consider to be the preferred embodiments of my invention, along with suggested modified forms, and it will be obvious to those skilled in the art that other changes may be made without departing from the scope of my invention as defined by the appended claims.

I claim:

1. A sealing ring assembly for a blast furnace installation comprising in combination, a plurality of sealing ring segments having interlocking ends and adapted to be assembled in an annular course, a plurality of retaining ring segments adapted to be assembled in an annular course about the assembled sealing ring, and circumferentially adjustable clamping means coacting between adjacent ends of adjacent retaining ring segments to clamp and retain the sealing ring segments in assembled relation.

2. The sealing ring assembly of claim 1 wherein said clamping means includes an apertured lug on each end of each retaining ring segment and a connecting bolt adjustably extending through the apertured lugs on adjacent ends of adjacent retaining ring segments.

3. The sealing ring assembly of claim 1 wherein the retaining ring segments correspond to the sealing ring segments and are adapted to be adjustably secured together at their adjacent ends in surmounting relation over the interlocked ends of the sealing ring segments.

4. A sealing ring assembly for a blast furnace installation comprising in combination, a plurality of sealing ring segments each having one end grooved and a projecting tongue on the other end and adapted to be assembled in an annular course with the tongued and grooved ends of adjacent segments interlocked, a plurality of retaining ring segments each having an apertured lug at each end and adapted to be assembled in an annular course about the assembled sealing ring, a connecting bolt adapted to extend through adjacent apertured lugs on adjacent retaining ring segments, and a nut adjustably carried on one extremity of the bolt to interconnect and clamp the retaining ring segments in assembled relation about the assembled sealing ring.

5. A sealing ring assembly for a blast furnace installation comprising in combination, a plurality of sealing ring segments each having one end grooved and a projecting tongue on the other end and adapted to be assembled in an annular course with the tongued and grooved ends of adjacent segments interlocked, and a separable segmental retaining ring adapted to adjustably encircle and clamp the assembled sealing ring, and means for circumferentially adjusting the clamping pressure of the retaining ring.

6. In a blast furnace having an open cylindrical top with a cylindrical hopper closure rotatably disposed therein and defining an annular space therebetween, said furnace top having a separable segmental wall section providing access to the annular space, a sealing ring assembly including a plurality of sealing ring segments adapted to be individually inserted into the annular space through the open wall section, and a plurality of retaining ring segments adapted to be individually inserted through the open wall section about the respective sealing ring segments, said retaining ring segments each having means at their ends for adjustably clamping adjacent segments together as they are inserted about the sealing ring to provide a circumferentially adjustable clamp therefor, thereby permitting mounting and assembly of the sealing and retaining rings through a single access opening in the furnace top.

7. In a blast furnace having an open top with spaced inner and outer concentric walls defining an annular recess closed at the bottom and open at the top, a rotatable charging hopper having a closure and extending freely into the furnace tp, said hopper having an external surrounding sleeve adapted to rotatably seat in the annular recess in spaced relation between the concentric walls of the furnace top, a pair of annular lands spaced along and between the sleeve and the outer concentric wall, a sealing ring assembly including a plurality of sealing rings disposed in an annular course between adjacent lands and encircling the sleeve, and a separable and circumferentially adjustable retaining ring disposed in an annular course between adjacent lands and clamped about the assembled sealing ring.

8. A composite seal assembly for a blast furnace top having a revolving hopper and comprising, spaced sealing members forming a seal between the hopper and furnace top, each sealing member including a plurality of sealing ring segments having interlocking ends assembled in an annular course about the hopper, a separable segmental retaining ring adjustably encircling each sealing member, and means for supplying and causing a sealing material to flow in the space between the sealing members and against the escape of furnace gas at a pressure in excess of the furnace gas pressure acting on the sealing members between the hopper and the furnace top.

9. In a blast furnace having an open top with spaced inner and outer concentric vertical walls defining an annular recess closed at the bottom and open at the top, a charging hopper having a closure and rotatably extending into the furnace top for discharging material therein, said hopper having an external surrounding sleeve extending into the annular recess, means forming a plurality of vertically spaced annular seats between the sleeve and the outer wall, a plurality of annular sealing members each disposed within an annular seat and each encircling the hopper sleeve, each sealing member including a plurality of ringsegments having interfitting ends assembled in an annular course, a segmental retaining ring adjustably encircling each sealing member, a conduit for supplying and causing a liquid to flow through the outer Wall of the furnace top in the space between the sealing members and against the escape of furnace gas at a pressure in excess of the furnace gas pressure acting on the .sealing members within the annular recess, and other conduits communicating with the annular recess above and below the sealing members for discharging any liquid that escapes past the sealing memlrers.

10. In a blast furnace top having inner and outer concentric walls forming an annular recess adapted to rotatably receive a hopper sleeve in concentric relation therein, a plurality of sealing ring segments having interfitting ends assembled in an annular course between the hopper sleeve and the outer wall, a plurality of retaining ring segments adjustably interconnected together at their ends in an annular course and clamped about the assembled sealing ring, means coacting therewith to circumferentially adjust the clamping pressure of the retaining ring, said outer concentric wall having removable segmental wall portions corresponding to the sealing and retaining ring segments, whereby the wall portions may be selectively removed to provide access to the underlying sealing and retaining ring segments.

11. In a blast furnace having an open top with a hopper closure rotatably extending into the top and defining an annular space therebetween, the combination of a stufiing box for said closure, a plurality of sealing rings within said stufiing box, said rings being spaced apart sufficiently to provide cavities therebetween, and means for introducing a fluid into one of said cavities and for causing the fluid to flow in the cavities between the rings against the escape of furnace gas, and including means for maintaining the fluid at a pressure in excess of the pressure of gas within the furnace to provide a multiple stage dynamic seal therefor.

12. The apparatus of claim 11 wherein the fluid introduced into said cavity is an inert gas.

13. The apparatus of claim 11 wherein the fluid introduced into said cavity is in the form of a grease.

References Cited in the file of this patent UNITED STATES PATENTS Baier Oct. 21, 1952' 

